The long-term objective of this project is to elucidate the neural and behavioral actions of anabolic-androgenic steroid(s) (AAS). Although the majority of published research focuses on males, it has been shown that women and adolescent girls take AAS to improve athletic performance and to achieve a muscular physique. We have demonstrated that individual AAS have discrete and quantifiable effects on the estrous cycle and sexual receptivity in adult rats. The goal of the present proposal is to extend our analysis of AAS effects to include motivation for sexual behavior and to delineate the physiological mechanisms by which AAS affect the nervous system in female rats. First, we will broaden our analysis of AAS effects on female sexual behavior and physiology and address the following questions: (a) does prepubertal AAS administration alter the onset of puberty and produce short- or long-term changes in estrous cyclicity or fertility, (b) do AAS given in combination act synergistically or antagonistically to alter the estrous cycle or sexual behavior, and (c) do AAS alter sexual behaviors that underlie motivation that may be comparable to libido in humans? Second, we will test the role of three brain areas (ventromedial hypothalamus, preoptic area, and lateral septum) rich in androgen and estrogen receptors, in the inhibition of sexual behavior by AAS. Specifically, (a) does direct application of AAS to these brain regions produce effects on behavior that mimic systemic administration, and (b) does the ability of AAS to modulate sexual behaviors at these central sites depend on signaling through steroid (androgen or estrogen) receptors? Third, we will test the possibility that AAS may alter sexual behaviors by acting at gamma-aminobutyric acid type A (GABAa) receptors, because transmission mediated by the GABAergic system is known to modulate sexual behavior. Expressly, does the central administration of AAS modulate sexual behaviors via effects on neuroendocrine processes underlying the AAS modulation of female sexual behavior. Characterizing AAS effects on the central nervous and endocrine systems in laboratory animals will provide valuable scientific evidence that will improve our understanding not only of the physiological and behavioral responses to high dose AAS abuse in women, but also to other naturally occurring disorders that are accompanied by androgen excess, such as polycystic ovarian syndrome.